A third and more specific prediction from the DM is that, relative to FH− groups, FH+ groups might respond more to the stimulant effects of alcohol on the ascending limb of the BAC curve in particular. In samples that assessed stimulant response on the ascending limb, however, there was a small-to-moderate, non-significant effect in the opposite direction, g = −0.37 (95% CI: −0.93, 0.20). In samples that assessed stimulant response on the descending limb, the mean effect size was also in the opposite direction, moderate, and not significantly different from zero, g = −0.49 (95% CI: −1.02, 0.05). Additionally, there was significant heterogeneity in stimulation effect sizes on the ascending and descending limbs of the BAC curve, Qwithin(3) = 11.06, p = .01, I2 = 72.89 and Qwithin(5) = 16.78, p = .01, I2 = 70.21, respectively. As shown in Table 4, effect-size estimates for sedation similarly did not appear to differ across the ascending and descending limbs, although there was significant heterogeneity across studies on the ascending, Qwithin(6) = 15.59, p = .02, I2 = 61.51, but not the descending, Qwithin(7) = 12.38, p = .09, I2 = 43.43, limb.
